1. Field of the Invention
The invention relates to head restraint guide sleeves for slidably supporting a head restraint of a seat assembly for an automotive vehicle.
2. Description of the Prior Art
Automotive vehicles include seat assemblies for supporting occupants within the vehicle. Seat assemblies typically include a seat cushion and a seat back operatively coupled to the seat cushion for pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined seating positions. Seat assemblies also typically include an adjustable head restraint for supporting the head of an occupant seated on the seat assembly. The head restraint is typically movable between a plurality of head support positions relative to the seat back to accommodate a range of occupant heights.
It is widely practiced in the seating art to support the head restraint at the top of the seat back with a parallel and spaced apart pair of rigid guide posts. Each of the guide posts extends from the head restraint through a corresponding pair of holes in the seat back. More specifically, a guide sleeve is inserted into each of the holes. Each guide sleeve includes a longitudinal bore extending axially through the sleeve for slidably receiving a guide post therethrough. A plurality of notches is arranged longitudinally along one or both of the guide posts representing the corresponding plurality of head support positions. A pin, engagable with any one of the plurality of notches to maintain the head restraint in the corresponding head support position, is operatively coupled with the guide sleeve for movement in and out of engagement with the plurality of notches. The pin is spring biased into engagement with the plurality of notches. An example of such a typical head restraint guide sleeve is shown in U.S. Pat. No. 6,099,077, which issued to Isaacson on Aug. 8, 2000.
In use, while the vehicle is being driven, it is common for buzzing, squeaking or rattling noises or xe2x80x9cBSRxe2x80x9d to occur at the interfaces of the guide sleeves, the guide posts, and the seat back. It is known to include longitudinal ribs extending generally radially outwardly from the outer periphery of the sleeve to minimize BSR between the guide sleeve and the seat back. An example of such ribs is shown in the U.S. Pat. No. 6,296,316 B1, which issued to Hann on Oct. 2, 2001. Similarly, it is known to include longitudinal ribs extending generally radially inwardly from the inner walls of the longitudinal bore to minimize BSR between the guide sleeve and guide post. An example of such ribs is shown in the U.S. Pat. No. 5,788,250, which issued to Masters et al. on Aug. 4, 1998. While longitudinal ribs are effective at minimizing BSR between the guide sleeve, guide post and seat back, it has been shown that such longitudinal ribs often result in higher efforts required to move the head restraint between the plurality of head support positions. The higher efforts are due in large part to unfavorable dimensional tolerance conditions ultimately resulting in excessive interference between the guide sleeve and the guide post.
Accordingly, it remains desirable to provide a head restraint guide sleeve design that minimizes BSR without sacrificing the desire for low head restraint adjustment efforts.
A guide sleeve is provided for receiving and supporting a guide post of a head restraint within a seat back frame of a seat assembly. The guide sleeve includes a body extending longitudinally between opposite upper and lower ends and a bore defined by cylindrical inner walls extending between the upper and lower ends of the body for slidably receiving the guide post therethrough for allowing selective adjustment of the head restraint relative to the seat back between a plurality of head supporting positions. A plurality of rings each projects circumferentially outwardly from the body and are deformable against the seat back frame during insertion of the guide sleeve into a hole formed in the seat back frame for creating an interference fit between the guide sleeve and the seat back frame without deforming the bore, and thereby, not increasing efforts required to slide the guide post through the bore during movement of the head restraint between the plurality of head supporting positions.